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