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