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