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