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