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