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)(19,20)(22,23)(25,26,30,29)(27,31,33,35)(28,32,38,37)(34,39,36,40)(1,2,5,4)(3,6,7,8)(9,10,12,14)(11,13,16,15)(17,18,21,24)(19,22,20,23)(26,29)(27,33)(32,37)(34,36)(9,10)(11,13)(12,14)(15,16)(17,19,21,20)(18,22,24,23)(25,27)(26,31)(28,36)(29,35)(30,33)(32,40)(34,38)(37,39)(1,3)(2,6)(4,8)(5,7)(9,10)(11,13)(12,14)(15,16)(17,18)(19,22)(20,23)(21,24)(25,28,30,38)(26,32,29,37)(27,34,33,36)(31,39,35,40)(1,4,5,2)(3,8,7,6)(9,11,12,16)(10,13,14,15)(17,20,21,19)(18,23,24,22)(25,29,30,26)(27,35,33,31)(28,37,38,32)(34,40,36,39)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.