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