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