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)(13,14,16,21,17,22,26,28)(15,20,25,27,24,18,23,19)(2,3)(5,6)(7,11)(8,10)(9,12)(13,15)(14,18)(16,25)(17,24)(19,21)(20,22)(23,26)(27,28) involution — undirected(5,7,8,12)(6,9,10,11)(13,15)(14,19)(16,23)(17,24)(18,21)(20,28)(22,27)(25,26)(1,3,4,2)(7,12)(9,11)(13,15)(14,20)(16,25)(17,24)(18,22)(19,28)(21,27)(23,26)(6,10)(9,11)(13,16,17,26)(14,21,22,28)(15,23,24,25)(18,27,20,19)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.