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