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