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