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