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