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