Automatic graph drawing with TikZ

graph-drawing.tex

% All you have to do is replacing `{a/1/2, b/3/4, c/2/1, d/3/2}` and `{a/b, b/c, c/d}`.
% With given example, node (a) will be drawn at coordinate (1,2), (b) in at (3,4), ...,
% and edges a-b, b-c, c-d will be drawn.
% Within `scope` environment, all nodes will be surrounded with circle.
\documentclass{standalone}
\usepackage{tikz}
\usepackage{amsmath, amssymb}
\usepackage{pgffor}
\begin{document}
	\begin{tikzpicture}
		\begin{scope}[every node/.style={draw,circle}]
			% draw nodes
			\foreach \name/\xx/\yy in {a/1/2, b/3/4, c/2/1, d/3/2}{
				\node (\name) at (\xx, \yy) {\name};
			}
			% draw edges
			\foreach \edgefrom/\edgeto in {a/b, b/c, c/d}{
				\draw (\edgefrom) -- (\edgeto);
			}
		\end{scope}
	\end{tikzpicture}
\end{document}

Preview: