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