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