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