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