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