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