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