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