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