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