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