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