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)(14,18)(19,24)(21,25)(26,28) involution — undirected(5,7,8,12)(6,9,10,11)(14,19)(15,22)(17,20)(18,24)(21,25)(23,27)(1,2,3,4)(6,10)(7,12)(13,14,20,24,16,18,17,19)(15,21,27,28,23,25,22,26)(6,10)(9,11)(15,23)(21,25)(22,27)(26,28) involution — undirected(13,15,20,27,16,23,17,22)(14,21,24,28,18,25,19,26)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.