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