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