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