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