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