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