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