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