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