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)(11,17)(16,21)(19,23)(25,26,31,33,29,35,30,36)(27,37,40,34,38,32,28,39)(1,3,5,4)(2,6,8,7)(9,10,13,14)(11,18,17,15)(12,16,20,21)(19,24,23,22)(25,27,29,38)(26,32,35,37)(28,31,40,30)(33,39,36,34)(1,3,5,4)(2,7,8,6)(9,11,13,17)(10,15,14,18)(12,19,20,23)(16,22,21,24)(26,33)(27,38)(30,31)(32,34)(35,36)(37,39)(1,4,5,3)(2,6,8,7)(12,20)(16,21)(19,23)(22,24)(25,28)(26,34)(27,31)(29,40)(30,38)(32,33)(35,39)(36,37)(9,12,13,20)(10,16,14,21)(11,19,17,23)(15,22,18,24)(26,35)(27,38)(28,40)(33,36)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.