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