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