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