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