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