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