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