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