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