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