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