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