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