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