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