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