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