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