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