If you set up the nodes N and M on a pair of circles centred around the same point, you can get quite a variety of nice looking diagrams. As part of playing around with generating svg images using d3js, I set up a page that allows you to create some 'bipartite art.' Some of the diagrams turned out nicely, particularly when you hide the nodes completely:
Try it out at: https://dmackinnon1.github.io/bipartite2.html
