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)(13,21)(14,18)(15,19)(16,20)(17,24)(22,25)(23,26) involution — undirected(4,7)(8,10)(11,13)(12,17)(14,23)(15,24)(16,22)(18,25)(19,21)(20,26) involution — undirected(3,5)(4,8)(6,9)(7,10)(12,18)(13,22)(14,16)(19,20)(23,24)(25,26) involution — undirected(5,9)(8,10)(11,14,15,16)(12,18,19,20)(13,23,24,22)(17,25,21,26)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.