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