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