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