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