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