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)(13,14,20,15)(16,26,27,28)(17,22,21,25)(18,24,19,23)(1,2,3,4)(7,8)(10,12)(13,15,18,24,20,14,19,23)(16,17,25,26,27,21,22,28)(5,7,9,8)(6,10,11,12)(13,16,19,22,20,27,18,25)(14,21,24,26,15,17,23,28)(5,8,9,7)(6,10,11,12)(13,17)(14,22)(15,25)(16,23)(18,26)(19,28)(20,21)(24,27)(16,27)(17,21)(22,25)(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.