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