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