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