Consult about an off-the-shelf library that can product good looking diagrams by specifying a set of connections. they should also be movable.
I've attached the following:
1. a test with direct lines where we did an a manual setting, note that the direct lines are not good
2. a diagram of what we need
1. the off-the-shelf solution
2. generate the enclosed 'required [url removed, login to view]' with it