One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,8)(3,7,4,6)(9,10)(11,19)(12,22)(13,16)(14,18)(15,20)(17,23)(21,24)(25,26,29,32)(27,33,34,40)(28,37,35,31)(30,38,39,36)(1,3,5,4)(2,6,8,7)(9,11,13,20)(10,15,16,19)(12,23,21,14)(17,22,18,24)(27,34)(28,35)(31,37)(33,40)(9,12,23,11,13,21,14,20)(10,15,18,24,16,19,17,22)(25,27,35,38,29,34,28,36)(26,30,37,40,32,39,31,33)(1,4,5,3)(2,7,8,6)(10,16)(15,19)(17,18)(22,24)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.