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