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