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