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