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