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