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