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)(25,26,29,31)(27,33,35,40)(28,37,34,32)(30,38,39,36)(9,10)(11,14)(12,13)(15,16)(17,19,20,23)(18,21,22,24)(25,27,34,38,29,35,28,36)(26,30,37,40,31,39,32,33)(1,3,4,8)(2,5,6,7)(10,13)(14,16)(19,23)(21,24)(26,31)(30,39)(32,37)(33,40)(9,11,12,15)(10,14,13,16)(18,22)(21,24)(26,31)(27,35)(32,37)(36,38)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.