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