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