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