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