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