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