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