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