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