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