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