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