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