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