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