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