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