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