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