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