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