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