One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(3,4)(5,6)(7,8)(9,10)(12,15)(16,18)(20,23)(24,26) involution — undirected(4,8)(5,9)(19,20)(21,24)(22,23)(25,26) involution — undirected(3,4,7,8)(5,6,9,10)(11,12,14,15)(13,16,17,18)(3,5,7,9)(4,6,8,10)(3,6)(4,9)(5,8)(7,10)(11,13,14,17)(12,16,15,18)(19,21,22,25)(20,24,23,26)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.