\documentclass{standalone}
\input{common-headers}
\input{sigles}
\begin{document}

\begin{tikzpicture}[auto,
  mout/.style={->,shorten >=1pt, >=Stealth, semithick},
  leg/.style={inner sep=1pt,font=\scriptsize,yshift=-1pt}
]
  \node (S)    at (0cm, 0cm)    {\includegraphics[width=2.5cm]{figures/operateursS}   };
  \node (fS)   at (3cm, 1.5cm)  {\includegraphics[width=2.5cm]{figures/operateursfS}  };
  \node (StfS) at (6cm, 1.5cm)  {\includegraphics[width=2.5cm]{figures/operateursStfS}};
  \node (StS)  at (3cm,-1.5cm)  {\includegraphics[width=2.5cm]{figures/operateursStS} };
  \node (fStS) at (6cm,-1.5cm)  {\includegraphics[width=2.5cm]{figures/operateursfStS}};
  \node (LkS)  at (9cm, 0cm)  {\includegraphics[width=2.5cm]{figures/operateursLkS} };

  \node[leg] at (S.south)     {$S$};
  \node[leg] at (fS.south)    {$\fermeture{S}$};
  \node[leg] at (StS.south)   {$\etoile{S}$};
  \node[leg] at (StfS.south)  {$\etoile{\fermeture{S}}$};
  \node[leg] at (fStS.south)  {$\fermeture{\etoile{S}}$};
  \node[leg] at (LkS.south)   {$\liaison{S}$};

  \draw [mout] (S)          to [out = -60, in = 180] node [swap] {$\etoile{\textvisiblespace}$}  (StS);
  \draw [mout] (S)          to [out =  60, in = 180] node        {$\fermeture{\textvisiblespace}$}  (fS);
  \draw [mout] (fS)         to [out =  60, in = 120] node [swap] {$\etoile{\textvisiblespace}$}  (StfS);
  \draw [mout] (StS)        to [out = -60, in =-120] node        {$\fermeture{\textvisiblespace}$}  (fStS);
  \draw [semithick] (StfS.east) to [out = 0, in = 180] (LkS.west);
  \draw [semithick] (fStS.east) to [out = 0, in = 180] (LkS.west);
  \node (LkSt) at (7cm,0cm) {$\textvisiblespace - \textvisiblespace$};
\end{tikzpicture}

\end{document}