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