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