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