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