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