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