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