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