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