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