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