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