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