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