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