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