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