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