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