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