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