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