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