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