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