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