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