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