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