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