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