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