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