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