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