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