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