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