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