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