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