One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,5)(4,6)(7,8)(9,10,12,15)(11,13,16,14)(20,27)(22,29)(23,28)(25,31)(2,5)(3,8)(6,7)(17,18,21,24)(19,22,26,29)(20,28,27,23)(25,32,31,30)(10,13)(11,16)(14,15)(17,19)(18,22)(20,25)(21,26)(23,30)(24,29)(27,31)(28,32) involution — undirected(2,6)(5,7)(17,20,21,27)(18,23,24,28)(19,25,26,31)(22,30,29,32)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.