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