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