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