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