This is a working example of rendering Lightning:RecordEditForm dynamically as per object's page layout

LightningRecordEditForm.xml

<aura:component implements="flexipage:availableForAllPageTypes" access="global" controller="LightningRecordEditFormController">

    <aura:attribute name="disabled" type="Boolean" default="false" />
    <aura:attribute name="layoutSections" type="List" />
    <aura:attribute name="saved" type="Boolean" default="false" />
    <aura:attribute name="showSpinner" type="Boolean" default="true" />
    <aura:attribute name="fieldName" type="String" default="StageName" />
    
    <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>
    <lightning:card title="">
        <aura:if isTrue="{!v.showSpinner}">
            <lightning:spinner />
        </aura:if>
        <aura:if isTrue="{!!v.saved}">
            <lightning:recordEditForm
                onload="{!c.handleLoad}"
                onsubmit="{!c.handleSubmit}"
                onsuccess="{!c.handleSuccess}"
                objectApiName="Contact">
                <!-- the messages component is for error messages -->
                <lightning:messages />
                
                <aura:iteration items="{!v.layoutSections}" var="section">
                    <div class="slds-section slds-is-open">
                    	<h3 class="slds-section__title">
                            {!section.label}
                        </h3>
                        <div class="slds-section__content">
                            <lightning:layout multipleRows="{!section.totalColumns > 1 }">

                                <aura:iteration items="{!section.lstFields}" var="field">

                                    <lightning:layoutItem size="{! 12/section.totalColumns }" flexibility="auto" padding="around-small">
                                        <aura:if isTrue="{!(!field.isReadOnly)}">
                                            <lightning:inputField fieldName="{!field.fieldName}" />	
                                            <aura:set attribute="else">
                                                <lightning:outputField fieldName="{!field.fieldName}" />	 
                                            </aura:set>
                                        </aura:if>
                                    </lightning:layoutItem>

                                </aura:iteration>
                         </lightning:layout>
                        </div>
                    </div>
                </aura:iteration>
                <lightning:layout verticalAlign="center" class="x-large">
                	<lightning:layoutItem padding="around-large"> 
                        <div class="slds-m-top_medium">
                        	<lightning:button disabled="{!v.disabled}" variant="brand" type="submit" name="save" label="Save" />
                    	</div>
                    </lightning:layoutItem>   
            	</lightning:layout>
            </lightning:recordEditForm>
            <aura:set attribute="else">
                <p>Saved!</p>
            </aura:set>
        </aura:if>
    </lightning:card>
</aura:component>

LightningRecordEditFormController.cls

public class LightningRecordEditFormController {
	
    @AuraEnabled 
    public static List<LayoutSection> getPageLayoutFields() {
        
        List<LayoutSection> lstSections = new List<LayoutSection>();
        
        try {
            // Provide the page layout name here
            // You can give multiple page layout names here as well
            List<String> componentNameList = new List<String>{'Contact-Contact Layout'};
            // Retrieve page layout details 
            List<Metadata.Metadata> components = Metadata.Operations.retrieve(Metadata.MetadataType.Layout, componentNameList);
            Metadata.Layout contLayout = (Metadata.Layout) components.get(0);
            
            // We are going to find the fields names and will keep them according to columns so 
            // we can show them as per page layout 
            for( Metadata.LayoutSection ls : contLayout.layoutSections ) {
                
                LayoutSection section = new LayoutSection( ls.label, ls.layoutColumns.size() );
                      
                List<LayoutColumn> lstColumns = new List<LayoutColumn>();
                Integer maxFieldsInColumn = 0;
                for( Metadata.LayoutColumn lc : ls.layoutColumns ) {
                    
                    LayoutColumn column = new LayoutColumn();
                    // check if there are fields available in that column
                    if( lc.layoutItems != null ) { 
                        // Get the max number of fields in a column to preserve the alignment 
                        if( maxFieldsInColumn < lc.layoutItems.size() ) {
                            maxFieldsInColumn = lc.layoutItems.size();
                        }
                        for( Metadata.LayoutItem li : lc.layoutItems ) {
                            
                            // Pass the LayoutItem object in the LayoutField consturctor	    
                            column.lstFields.add( new LayoutField( li ) );
                        }
                    }
                    // No need to add a column in the section if there is no field available 
                    if( column.lstFields.size() > 0 ) {
                    	lstColumns.add( column );
                    }
                }
                
                // Now, we need to arrange the fields in section so we can use them in the iteration 
                // on the component so we will have to arrange them in the order 
                if( maxFieldsInColumn > 0 ) {
                    for( Integer i = 0; i < maxFieldsInColumn; i++ ) {
                        for( Integer j = 0; j < lstColumns.size(); j++ ){
                            if( lstColumns[j].lstFields.size() > i ) {
                            	section.lstFields.add( lstColumns[j].lstFields[i] );    
                            }    
                            else {
                                section.lstFields.add( new LayoutField() );
                            }
                        }    
                    }    
                }
                
                lstSections.add( section );
            }
        }
        catch( Exception e ){
            System.assert(false, e.getLineNumber() + ' : ' + e.getMessage() );
        }
        return lstSections;
    }
    
    public class LayoutSection {   
	@AuraEnabled public String label;
    	@AuraEnabled public List<LayoutField> lstFields;
        @AuraEnabled public Integer totalColumns;
        public LayoutSection( String label, Integer totalColumns ) {
	    this.label = label;
            this.totalColumns = totalColumns;
            this.lstFields = new List<LayoutField>();
        }
    }
    
    private class LayoutColumn {
    	private List<LayoutField> lstFields;    
        public LayoutColumn() {
            this.lstFields = new List<LayoutField>();
        }
    }
    
    public class LayoutField {
        @AuraEnabled public String fieldName;
        @AuraEnabled public Boolean isRequired;
        @AuraEnabled public Boolean isReadOnly;
        
        public LayoutField() {}
        
        public LayoutField( Metadata.LayoutItem li ) {
        	
            this.fieldName = li.field;
            if( li.behavior == Metadata.UiBehavior.Required ) {
                this.isRequired = true;
            }
            else if( li.behavior == Metadata.UiBehavior.ReadOnly ) {
                this.isReadOnly = true;
            }    
        }
    }
}

LightningRecordEditFormController.js

({
    doInit: function( component, event, helper ) {
        var action = component.get("c.getPageLayoutFields");
		action.setCallback(this, function(response) {
        	var state = response.getState();
			if (state === "SUCCESS") {
                component.set("v.layoutSections", response.getReturnValue() );
                console.log( response.getReturnValue() );
            }
            else if (state === "INCOMPLETE") {
            }
            else if (state === "ERROR") {
                var errors = response.getError();
				console.log( errors );
            }
        });
        
        $A.enqueueAction(action);
    },
    
    
	handleSuccess : function(component, event, helper) {
        var toastEvent = $A.get("e.force:showToast");
        toastEvent.setParams({
            "title": "Success!",
            "message": "The property's info has been updated.",
            "type": "success"
        });
        toastEvent.fire();
        
    },
    handleLoad : function(component, event, helper) {
    	component.set("v.showSpinner", false);   
    },
    handleSubmit : function(component, event, helper) {
       
    }
})