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