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