\begin{tikzpicture}

\node[shape=circle,draw=green] (0) at (0,0) {0};
\node[shape=circle,draw=green] (1) at (3.5,-0.5) {1};
\node[shape=circle,draw=green] (2) at (7.5,4.5) {2};
\node[shape=circle,draw=red] (3) at (7.5,0) {3};
\node[shape=circle,draw=red] (4) at (3,2.5) {4};


\node[below] at (0,-0.4) {$a$};
\node[below] at (3.5,-1) {$b$};
\node[below] at (2.5,3) {$c$};
\node[below] at (7.5,-0.4) {$d$};
\node[below] at (8,4.5) {$e$};

\path [<-, draw = brown](0) edge (1);
\path [<-, draw = red](1) edge (2);
\path [<-, draw = blue](2) edge (3);
\path [<-, draw = green](3) edge (4);


\path [->](4) edge[bend right=40] (2); 


\path [->](3) edge[bend right=40] (1); 


\path [->](2) edge[bend right=40] (0); 


\end{tikzpicture}