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