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