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