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