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)(13,14,17,19)(15,16,20,18)(21,22)(23,24)(25,28)(26,27)(6,10)(8,11)(13,14,17,19)(15,16,20,18)(22,27)(23,25)(5,7)(6,11)(8,10)(9,12)(13,15,17,20)(14,18,19,16)(21,23,26,25)(22,28,27,24)(1,2)(3,4)(5,7)(6,8)(9,12)(10,11)(13,15)(14,16)(17,20)(18,19)(21,24)(22,23)(25,27)(26,28) involution — undirected(5,8)(6,12)(7,10)(9,11)(13,16)(14,15)(17,18)(19,20)(21,25,26,23)(22,28,27,24)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.