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)(12,17)(16,22)(20,23)(25,26)(27,34)(28,38)(29,30)(31,33)(32,37)(35,36)(39,40) involution — undirected(2,5)(6,7)(9,10)(11,17)(12,19)(13,16)(14,15)(18,23)(20,24)(21,22)(25,27)(26,32)(28,35)(29,39)(30,36)(31,37)(33,34)(38,40) involution — undirected(1,2)(3,6)(4,5)(7,8)(13,21)(16,22)(18,24)(20,23)(25,28,31,29)(26,30,33,38)(27,35,37,39)(32,36,34,40)(1,3,4,8)(2,6,5,7)(9,11,14,19)(10,12,15,17)(13,18,21,24)(16,20,22,23)(25,29,31,28)(26,30,33,38)(27,35,37,39)(32,40,34,36)(9,12)(10,11)(13,20)(14,17)(15,19)(16,18)(21,23)(22,24)(25,27)(26,32)(28,35)(29,39)(30,36)(31,37)(33,34)(38,40) involution — undirected(9,13)(10,16)(11,18)(12,20)(14,21)(15,22)(17,23)(19,24)(25,30)(26,28)(27,36)(29,33)(31,38)(32,35)(34,39)(37,40) 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.