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