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