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