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