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