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