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