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