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