Simple FSA

digraph {
    rankdir=LR;
    node [shape=doublecircle]; q0; q3;
    node [shape=point]; qi;
    node [shape=circle];
    qi -> q0;
    q0 -> q1 [label="E"];
    q1 -> q2 [label="+"];
    q1 -> q2 [label="-"];
    q2 -> q3 [label="0-9"];
    q3 -> q3 [label="0-9"];
    q1 -> q3 [label="0-9"];
}