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