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