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