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