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