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