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