\begin{figure}[H]
  \begin{center}
    \unitlength=4pt
    \begin{picture}(45, 41)(0,-17)
    \gasset{Nw=5,Nh=5,Nmr=2.5,curvedepth=0}
    \thinlines
    \node[Nmarks=if,iangle=180,fangle=180](A0)(0,0){$1$}
    \node[Nmarks=f,fangle=90](A1)(15,15){$2$}
    \node(A)(25,0){$0$}
    \node[Nmarks=f,fangle=0](A3)(45,0){$4$}
    \node(A4)(15,-15){$5$}
    \node[Nmarks=f,fangle=0](A5)(35,-15){$6$}
    \node[Nmarks=f,fangle=0](A12)(35,15){$3$}
    \drawedge(A0,A1){$a$}
    \drawedge[ELside=r](A0,A4){$b$}
    \drawedge(A1,A12){$a$}
    \drawedge(A1,A){$b$}
    \drawedge[ELside=r](A3,A){$b$}
    \drawedge[ELside=r](A4,A){$b$}
    \drawedge[ELside=r](A5,A){$a$}
    \drawloop[loopangle=180](A){$a,b$}
    \drawloop[loopangle=90](A12){$a$}
    \gasset{curvedepth=3}
    \drawedge(A12,A3){$b$}
    \drawedge(A3,A12){$a$}
    \gasset{curvedepth=2}
    \drawedge(A4,A5){$a$}
    \drawedge(A5,A4){$b$}
    \end{picture}
  \end{center}
  \caption{Le même, en renommant les états.}
\end{figure}