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