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