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