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