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