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