you can use VLANs
you can team nics
you can remove SW3 and use crossover cables
all surjections are welcome.
There is only a few rules:
1) Only the Management subnet or VLAN can access the physical machines and switches
2) the running vm are 2 only know about their virtual switches and the LAN (aka cloud)
3) The PC AD/DC is only for the nodes and storage, if the VM's need a DC, it will be a VM.
4) Try to limit the network traffic/congestion as mush as possible
5) use the color code below or more if needed

if the above image is not shown try this link http://i44.tinypic.com/14lofgg.png
Thanks