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