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