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