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