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