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