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