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