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