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