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