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