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