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