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