Max De Marzi has a truly amazing series of posts on graph visualization and Neo4j!
Here is a quick list:
Highlights (besides Max’s code): Processing.js, radial navigation (Donut).
Graph Visualization and Neo4j – Part Two
Highlights: Continues with Processing.js and the canvas element from HTML 5. If you don’t know the canvas element, see the Mozilla Developer page Canvas tutorial.
Graph Visualization and Neo4j – Part Three
Highlights: D3.js, chord flare visualization, and to answer Max’s question about the resulting graphic: Yes, yes it is pretty!