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