\documentclass{standalone}
\usepackage{binarytree}
\usetikzlibrary{graphs}

\begin{document}
\btreeset{math labels,scale=0.7}
\begin{tikzpicture}
  \BinaryTree[local bounding box=INIT]{%
    :1!l:w!r:x:red!l:\sigma,ll!l:\sigma,lr!r:\sigma,
    r:w!r:y!r:\sigma,rr!l:\sigma,rl!l:\sigma}{3}
  \BinaryTree[local bounding box=FINAL,xshift=10cm]{
    :1!l:w!l:x':red!l:\sigma,lr!r:\sigma,ll!r:\sigma,
    r:w!r:y!r:\sigma,rr!l:\sigma,rl!l:\sigma}{3}
  \graph[use existing nodes]{ INIT -> FINAL};
\end{tikzpicture}
\end{document}
