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