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