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