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