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