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