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