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