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