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