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