One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(9,10,14,21,16,22,15,20)(11,19,13,17,25,32,24,33)(12,26,29,18,30,35,28,36)(23,31,37,34,38,40,27,39)(1,2,3,4)(5,6)(7,8)(9,11,14,13,16,25,15,24)(10,17,20,19,22,33,21,32)(12,23,28,27,30,38,29,37)(18,31,35,34,36,40,26,39)(6,8)(9,12)(10,18)(11,23)(13,27)(14,28)(15,29)(16,30)(17,31)(19,34)(20,35)(21,26)(22,36)(24,37)(25,38)(32,39)(33,40) involution — undirected(9,13,14,25,16,24,15,11)(10,19,20,33,22,32,21,17)(12,27,28,38,30,37,29,23)(18,34,35,40,36,39,26,31)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.