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