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)(13,14,17,19)(15,16,20,18)(21,22,25,28)(23,24,27,26)(5,7,9,12)(6,8,10,11)(13,15,17,20)(14,18,19,16)(23,27)(24,26)(6,10)(7,12)(14,19)(16,18)(21,23,25,27)(22,26,28,24)(1,2,3,4)(5,7)(6,8)(9,12)(10,11)(13,16,17,18)(14,15,19,20)(21,24,25,26)(22,27,28,23)(5,8)(6,7)(9,11)(10,12)(13,15)(14,18)(16,19)(17,20)(21,22)(23,26)(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.