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