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