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