It appears that Dagre supports the creation of flowcharts. I'm searching for an example - will post back when I find one.
Edit: Here's something approaching a flowchart, generated from a directed graph: http://jsfiddle.net/5u9mzfse/47/
Edit2: Here's another example of a JS lib: https://gojs.net/latest/samples/flowchart.html. Perhaps you could write a CYPHER query that emits the model format.
Edit3: Here's one more tool (http://nomnoml.com/), built on Dagre, feed the model as text like this:
[more loot] no ->[<
^-- result like this. Again, perhaps you could write a CYPHER query to produce input format to the diagram tool.