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)(13,14,19,17,18,21,16,26)(15,22,23,28,24,20,27,25)(5,7)(6,9)(8,12)(10,11)(13,15)(14,20)(16,27)(17,25)(18,24)(19,23)(21,22)(26,28) involution — undirected(1,2,3,4)(13,16,18,19)(14,17,21,26)(15,23,24,27)(20,28,22,25)(7,12)(9,11)(14,21)(15,24)(17,26)(23,27) involution — undirected(6,10)(9,11)(13,17,19,21,18,26,16,14)(15,25,23,22,24,28,27,20)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.