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