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