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