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