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