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