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