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