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