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