One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,11)(8,9)(10,12) involution — undirected(1,2)(3,4)(6,9)(10,11)(13,14,18,19)(15,23,25,28)(16,22,17,21)(20,26,27,24)(2,4)(14,19)(20,27)(21,22)(23,28) involution — undirected(2,4)(13,15,18,25)(14,20,19,27)(16,24,17,26)(21,23,22,28)(5,7,8,12)(6,10,9,11)(13,16,18,17)(14,21,19,22)(15,24,25,26)(20,23,27,28)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.