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