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