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