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