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