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)(11,12)(13,14)(15,16)(26,27)(28,35)(29,37)(39,40)(2,4)(6,8)(10,14)(12,15)(18,21)(22,24)(25,26,30,27)(28,33,35,31)(29,34,37,32)(36,39,38,40)(17,18)(19,22)(20,21)(23,24)(25,27,30,26)(28,33,35,31)(29,34,37,32)(36,40,38,39)(1,3)(2,6)(4,8)(5,7)(9,11,13,16)(10,15,14,12)(17,19,20,23)(18,22,21,24)(25,28,30,35)(26,31,27,33)(29,38,37,36)(32,40,34,39)(1,4,5,2)(3,6,7,8)(9,12,13,15)(10,11,14,16)(25,29,30,37)(26,32,27,34)(28,36,35,38)(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.