\documentclass[convert]{standalone}
\usepackage{amsmath}
\usepackage{tikz}
\usetikzlibrary{automata,arrows}
\tikzset{->,>=stealth',auto,node distance=2cm,thick,initial text=}
\begin{document}
\begin{tikzpicture}
    \tikzstyle{every state}=[fill opacity=0.5,text opacity=1,semithick,minimum size=17pt, opacity=0.2]

    \node[state] (1) at (1, 0) [opacity=1] {1};
    \node[state] (2) at (2, 0) [opacity=1] {1};
    \node[state] (4) at (4, 0) [opacity=1] {1};
    \node[state] (5) at (5, 0) [opacity=1] {1};

    %\node[state] (8) at (0.5, 1) [opacity=1] {1};
    %\node[state] (9) at (2.5, 1) [opacity=1] {1};
    \node[state] (10) at (4.5, 1) [opacity=1] {2};

    \node[state] (12) at (1.5, 2) [opacity=1] {2};
    %\node[state] (13) at (5.5, 2) [opacity=1] {2};

    \node[state] (14) at (3.5, 3) [opacity=1] {4};

    \node (15) at (0, -0.7) {0};
    \node (16) at (1, -0.7) {1};
    \node (17) at (2, -0.7) {2};
    \node (18) at (3, -0.7) {3};
    \node (19) at (4, -0.7) {4};
    \node (20) at (5, -0.7) {5};
    \node (21) at (6, -0.7) {6};
    \node (22) at (7, -0.7) {7};

    \draw
    (14) edge node[font=\tiny,left,pos=0.35] {0} (12)
    (12) edge[bend left] node[font=\tiny,right,pos=0.3] {10} (2)
    %(9)  edge node[font=\tiny,left,pos=0.3]  {0} (2)
    (12) edge[bend right] node[font=\tiny,left,pos=0.3]  {01} (1)
    %(8)  edge node[font=\tiny,right,pos=0.3] {1} (1)
    (14) edge[bend left] node[font=\tiny,right,pos=0.34]{10} (10)
    %(13) edge node[font=\tiny,left,pos=0.3]  {0} (10)
    (10) edge node[font=\tiny,left,pos=0.3]  {0} (4)
    (10) edge node[font=\tiny,right,pos=0.3] {1} (5)
    ;
\end{tikzpicture}
\end{document}