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