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)(17,18,21,24)(19,26,28,23)(20,30,22,25)(27,31,29,32)(1,3)(2,6)(4,7)(5,8)(17,19,21,28)(18,23,24,26)(20,29,22,27)(25,32,30,31)(9,11,12,16)(10,13,14,15)(18,24)(19,27)(20,22)(23,31)(26,32)(28,29)(2,7)(3,8)(10,14)(13,15)(18,24)(19,28)(25,30)(27,29) involution — undirected(1,4,5,6)(2,3,7,8)(17,20,21,22)(18,25,24,30)(19,29,28,27)(23,32,26,31)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.