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