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)(11,17)(12,22)(13,18)(14,23)(15,19)(16,20)(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)(10,16,18,17)(12,14,21,15)(19,24,23,22)(27,34)(28,35)(31,37)(33,40)(1,3,5,4)(2,7,8,6)(9,12,14,11,13,21,15,20)(10,17,19,22,18,16,23,24)(25,27,35,38,29,34,28,36)(26,30,37,40,32,39,31,33)(1,4,5,3)(2,7,8,6)(10,18)(16,17)(19,23)(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.