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