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