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