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)(15,23)(16,20)(17,21)(18,22)(19,26)(24,27)(25,28)(2,4)(6,9)(10,11)(13,14)(15,24)(16,19)(17,21)(18,28)(20,26)(22,25)(23,27) involution — undirected(5,7,8,12)(6,10,9,11)(13,15)(14,19)(16,25)(17,26)(18,27)(20,22)(21,23)(24,28)(13,16,17,27)(14,20,21,24)(15,25,26,18)(19,22,23,28)(14,21)(19,23)(20,24)(22,28) involution — undirectedA 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.