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