One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,7)(3,8,4,6)(9,10,12,15)(11,13,16,14)(17,18,22,26)(19,27,29,31)(20,25,21,24)(23,28,32,30)(1,3,5,4)(2,6,7,8)(19,28)(20,21)(23,31)(24,25)(27,32)(29,30)(1,4,5,3)(2,6,7,8)(10,13)(11,16)(14,15)(17,19)(18,23)(20,28)(21,30)(22,29)(24,31)(25,27)(26,32)(19,29)(23,32)(27,31)(28,30) involution — undirectedA 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.