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