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