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