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