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