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