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