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