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