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