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