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