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