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