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