Graphviz for very large state machine - graphviz

Question

I have a state machine that, despite having very few node (8), has a lot of connections.
How can I draw it using graphviz in a presentable way.
Currently I have this. The problem is that this is not presentable in any way. The arrows have an awkward shape, the states are all over the place...
digraph finite_state_machine {
rankdir="TB";
size="8,5"
{rank = same; 1 2}
{rank = same; 3 4}
{rank = same; 7 8}
1->7[label="<p,a>"];
1->5[label="<p,a>"];
1->3[label="<p,a>"];
1->1[label="<p,a>"];
2->7[label="<~(p),a>"];
2->5[label="<~(p),a>"];
2->3[label="<~(p),a>"];
2->1[label="<~(p),a>"];
3->7[label="<p,a>"];
3->5[label="<p,a>"];
3->3[label="<p,a>"];
3->1[label="<p,a>"];
4->7[label="<~(p),a>"];
4->5[label="<~(p),a>"];
4->3[label="<~(p),a>"];
4->1[label="<~(p),a>"];
5->8[label="<p,a>"];
5->7[label="<p,a>"];
5->6[label="<p,a>"];
5->5[label="<p,a>"];
5->4[label="<p,a>"];
5->2[label="<p,a>"];
6->8[label="<~(p),a>"];
6->7[label="<~(p),a>"];
6->6[label="<~(p),a>"];
6->5[label="<~(p),a>"];
6->4[label="<~(p),a>"];
6->2[label="<~(p),a>"];
7->8[label="<p,a>"];
7->7[label="<p,a>"];
7->6[label="<p,a>"];
7->5[label="<p,a>"];
7->4[label="<p,a>"];
7->2[label="<p,a>"];
8->8[label="<~(p),a>"];
8->7[label="<~(p),a>"];
8->6[label="<~(p),a>"];
8->5[label="<~(p),a>"];
8->4[label="<~(p),a>"];
8->2[label="<~(p),a>"];
}
Which yields this
Is there any way I can make the automata more presentable?

Answer 1

Some times it help setting e.g. minlen=2 on edges, and decorate=1 make it more obvious where labels belong, try adding the following:
edge[decorate=1 minlen=2]
node[width=2 height=2 fontsize=50]
you can have a bit control of arrow tails and heads using compass so you might like the following better:
1:n->1:n
7:s->7:s
8:s->8:s
instead of:
1->1
7->7
8->8
since you only have 2 kind of edge labels It might also help to have a edge color depending on the label
I sugest you try these kind of things out on http://viz-js.com/