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