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