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