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