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