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