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