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)(13,14,20,23)(15,18,22,19)(16,26,25,24)(17,21,28,27)(5,7)(6,9)(8,11)(10,12)(13,15,19,14,20,22,18,23)(16,24,27,17,25,26,21,28)(2,4)(7,11)(9,12)(13,16,19,27,20,25,18,21)(14,17,22,26,23,28,15,24)(7,11)(9,12)(13,17)(14,21)(15,25)(16,22)(18,24)(19,26)(20,28)(23,27) involution — undirected(6,10)(9,12)(13,18,20,19)(14,22,23,15)(16,21,25,27)(17,26,28,24)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.