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