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