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