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