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