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