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