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