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