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