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