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