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)(13,14)(17,18,22,21)(19,24,23,20)(25,26)(27,33)(28,31)(29,32)(30,35)(34,39)(36,37)(38,40)(3,8)(5,7)(10,13)(15,16)(18,21)(19,23)(25,26,29,32)(27,33,35,30)(28,36,37,31)(34,38,40,39)(9,11,14,12)(10,15,13,16)(17,19)(18,20)(21,24)(22,23)(25,26)(27,33)(28,31)(29,32)(30,35)(34,39)(36,37)(38,40)(1,3)(2,5)(4,8)(6,7)(9,12,14,11)(10,16,13,15)(17,20,22,24)(18,23,21,19)(25,27,29,35)(26,30,32,33)(28,34,37,40)(31,38,36,39)(1,2)(3,5)(4,6)(7,8)(9,13,14,10)(11,16,12,15)(17,21,22,18)(19,24,23,20)(25,28,29,37)(26,31,32,36)(27,34,35,40)(30,38,33,39)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.