I think you are putting the wrong thing in the center. Do not choose something that is connected to everything else in the map because then all the maps end up looking the same.
For instance, for child trafficking, leave that out of the map entirely. Instead have color codes for child prostitute, pimp, sex customer, slave buyer, slave seller or something like that. If it isn't clear at a glance then use Child Trafficking as a page title at the top. Don't worry about the layout until the connections show you where the clusters are in the map. That in itself is useful information to have. No need for a central node at all unless there actually is some person or org that is central