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)(13,14,17,16,18,20,25,27)(15,21,24,22,23,19,28,26)(5,6)(7,11)(8,10)(9,12)(13,14)(15,21)(16,25)(17,27)(18,20)(19,23)(22,28)(24,26) involution — undirected(2,4)(5,7)(6,9)(8,12)(10,11)(13,15,18,23)(14,19,20,21)(16,26,27,22)(17,24,25,28)(7,12)(9,11)(13,16,25,14,18,27,17,20)(15,22,28,21,23,26,24,19)(6,10)(9,11)(14,20)(15,23)(16,27)(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.