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