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