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