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