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