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