This chart type is not available in default chart list, but you can search through branch.qlik.com to find if there are extensions which can create this chart.
I've been trying to get the Network Vis Chart to work but i am struggling - did you manage to get it working? I don't suppose you have a Sample? Ive downloaded the sample Les Miserables but cant get the code to work!
Do you still need help with this? I also downloaded the Les Miserables file yesterday and had to panel beat it a bit to get it to work. You can send me (or post) your sample qvf and the dataset and I'll try to help.