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