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)(11,15)(12,17)(13,22)(14,18)(16,19)(20,24)(21,23)(25,26,30,33,31,28,29,34)(27,32,36,40,37,35,38,39)(2,5)(3,7)(9,11)(10,15)(12,21)(13,19)(14,20)(16,22)(17,23)(18,24)(25,27,30,36,31,37,29,38)(26,32,33,40,28,35,34,39)(1,3,4,7)(2,6,5,8)(9,11)(10,16)(12,19)(13,21)(14,20)(15,22)(17,24)(18,23)(25,28)(26,31)(27,35)(29,33)(30,34)(32,37)(36,39)(38,40)(2,5)(6,8)(9,12,14,13)(10,17,18,22)(11,19,20,21)(15,16,24,23)(25,29,31,30)(26,33,28,34)(27,36,37,38)(32,39,35,40)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.