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