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