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