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