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