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