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