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