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)(11,12)(13,20)(14,18)(15,23)(16,19)(17,21)(22,25)(24,26) involution — undirected(4,7)(8,10) involution — undirected(11,13)(12,17)(14,21)(15,24)(16,22)(18,25)(19,26)(20,23) involution — undirected(3,5,6,9)(4,8,7,10)(11,14,16,15)(12,18,19,23)(13,21,22,24)(17,25,26,20)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.