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