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