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