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