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