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)(16,21)(17,24)(18,22)(19,23)(25,27)(26,28) involution — undirected(6,10)(11,12)(13,15,19,26)(14,20,23,28)(16,24,27,22)(17,25,18,21)(1,2,3,4)(5,7,9,8)(6,11,10,12)(15,21)(16,20)(17,18)(22,24)(25,26)(27,28)(5,8,9,7)(6,12,10,11)(13,16)(14,21)(15,24)(17,20)(18,28)(19,27)(22,26)(23,25)(13,17)(14,22)(18,19)(20,28)(21,25)(23,24) 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.