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