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