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