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)(14,19)(16,17)(20,27)(21,26)(22,28)(24,25) involution — undirected(7,8)(10,12)(13,14)(15,22)(16,19)(17,26)(18,21)(20,23)(24,28)(25,27) involution — undirected(1,2,3,4)(5,7,9,8)(6,10,11,12)(13,15)(14,20)(16,24)(17,25)(18,23)(19,27)(21,22)(26,28)(5,8,9,7)(6,10,11,12)(14,21)(15,23)(19,26)(24,25)(6,11)(10,12)(13,16,18,17)(14,19,21,26)(15,24,23,25)(20,27,22,28)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.