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