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