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