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