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