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