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